Versatackle

The Versatackle is a method of gaining mechanical advantage with rope much like a block and tackle.

At both "A" and "B", put the loop of your choice. I prefer a Butterfly Loop for both. Take the extra rope coming from B and loop it through loop A, then back through B, then A, then B, etc.

Typically, you pull the free end through each loop 2 or 3 times, depending on the rope and the situation. Surprisingly, it is self-locking. That is, you can give a pull and when you release, the Versatackle's internal friction will hold the load.

Use for binding, clamping, pulling or whatever. The downside is that it can be hard on rope. If you're tying down a load on a truck, tie the butterfly a few feet off the bed, loop the rope down around a hook, and tie another butterfly with plenty of extra rope, just like loop B. You can figure out the rest from there. This concept is easily adapted to various uses.

You can also gain mechanical advantage with a rope in a little more involved method called the Spanish Windlass.